#include <WiFi.h>
#include <PubSubClient.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <ArduinoJson.h>

#include "DHTesp.h"




const char* ssid = "Wokwi-GUEST"; //declares a character array pointer ssid that points to a string literal "Wokwi-GUEST".
const char* password = "";
const char* mqtt_server = "broker.hivemq.com";
const char* stopic = "luuvachiase/led";
const char* ptopic = "luuvachiase/temp";
//const int oneWireBus = 4;  // dùng pin GPIO4

const int DHT_PIN = 15; // DHT22
char result_temp[10]; // Buffer big enough for 7-character float
char result_hum[10]; // Buffer big enough for 7-character float

WiFiClient espClient; //This object represents a TCP/IP client connection to a Wi-Fi network.
PubSubClient client(espClient); // This object uses the espClient object as its underlying TCP/IP connection to connect to a MQTT broker
unsigned long lastMsg = 0;

DHTesp dhtSensor; // Use DHTesp class and use its methods to initialize the sensor

void setup_wifi() {

  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

 // randomSeed(micros());

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    String clientId = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (client.connect(clientId.c_str())) { //The string is terminated by a null character ('\0') 
                                            //is also the case for a const char* pointer in C.
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish(ptopic, "hello world");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void publish_temp()
{
      TempAndHumidity  data_temp = dhtSensor.getTempAndHumidity(); // the getTemperature() and getHumidity() methods 
                                                                    //to read the temperature and humidity data, respectively
      dtostrf(data_temp.temperature, 6, 2, result_temp); // converts a floating-point number to a string, 
                                                          //and stores the result in a character array.
      dtostrf(data_temp.humidity, 6, 2, result_hum); // to a string with a width of 6 characters, including 2 digits to the right of the decimal point,

      DynamicJsonDocument json(100); //create a dynamic, in-memory representation of a JSON document. 
      //This means that the size of the document is not fixed at compile time, and can be adjusted at runtime as needed.
      json["temp"] = result_temp;
      json["humi"] = result_hum;

      String jsonString;
      serializeJson(json, jsonString); // that allows you to serialize a JSON data structure into a string.
      
      const char* payload = jsonString.c_str(); 
      Serial.print("Publishing: ");
      Serial.println(payload);
      client.publish(ptopic, payload);
      Serial.print("Done!");

}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");

  pinMode(12, OUTPUT);     // Initialize the BUILTIN_LED pin as an output
  pinMode(14, OUTPUT);  
  pinMode(13, OUTPUT); 
  Serial.begin(115200);
  // Start the DHT22 sensor
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22); // use the dhtSensor.setup() method to initialize the sensor and 
   // dhtSensor.begin() method is typically called in settup
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  
}

void loop() {
   if (!client.connected()) {
    reconnect();
  }
  client.loop();
  publish_temp();
  delay(3000);
}